1. Biochar Increases nutrient retention: like other forms of organic matter, biochar holds nutrients and releases them gradually. Biochar has a high surface area and CEC (cation exchange capacity) – this allows it to adsorb and retain nutrients such as nitrogen, phosphorus, and potassium. More biochar means less nutrients are lost in in the runoff water, and our waterways stay cleaner.
2. Biochar Enhances soil structure: Biochar has a unique structure that can help to improve soil porosity, water-holding capacity, and aeration. This improves the soil structure and allows roots to grow more deeply, increasing plant access to nutrients and water.
3. Biochar Stimulates beneficial microorganisms: Biochar can provide a habitat for beneficial microorganisms that can improve soil health and fertility. These microorganisms can help to break down organic matter, improve nutrient cycling, and suppress plant diseases.
4. Biochar Reduces soil acidity: Biochar has a high pH, which can help to neutralize acidic soils. This can improve nutrient availability and plant growth in acidic soils.
Biochar does not break down in the soil very fast - it can last hundreds of times longer than leaves and logs. Putting biochar into the soil is a long term improvement, it is an investment for many generations to come.
Adding too much carbon rich material to the soil at one time can actually tie up nutrients for a while. That is why some biochar advocates talk about “charging” the biochar by mixing it with compost or other fertilizer before adding it to the soil. Wood ash (which might be formed in the biochar making process) is a rich source of calcium and potassium.